1. Field of the Invention
The present invention is directed to an eye model. Specifically, the present invention is directed to an eye model for measurement by an ophthalmic diagnostic instrument for calibration and development purposes.
2. Description of Related Art
A difficulty in the development of ophthalmic diagnostic devices is obtaining information about the human eye, such as geometry, aperture diameter depth, etc. without incurring significant discomfort or injury to a human subject. The development of an ophthalmic diagnostic instrument requires repetitive gathering of information, and this can be painful and problematic for a human test subject.
An additional problem is the fact that the eye is a living organism and differs from one person to the next. Obviously, this compounds the problem of gathering accurate data about the eye geometry because there is no way to truly measure in-vivo tissue of the eye to the micron level without physically removing the eye.
Therefore, to develop an ophthalmic diagnostic instrument and to gather the information needed for the device development, artificial representations of the human eye have been developed. These artificial representations range from simple meniscus shapes filled with fluid to complex multiple part assemblies. One design that has been used as a spherical meniscus shape attached to an acrylic plate. The shape behind the meniscus is back-filled with a fluid that represents aqueous found in the human eye. The fluid is used to lower the reflection from the rear surface of the meniscus. Typically, these eye models do not incorporate the iris and lens into the model.
A common drawback to these types of assemblies, is the problem of evacuating air from behind the meniscus and keeping the air from entering the chamber and preventing fluid from escaping from the chamber. Air entering the artificial models then presents itself within the area to be measured by the diagnostic instrument. These air bubbles optically distort the information to be gathered and also disrupts the visual field thereby, preventing clean images of the surface from being obtained.
Therefore, it would be desirable to have a new eye model which overcomes these drawbacks and assures that fluid fills the chamber covering the area to be measured and sufficiently evacuates the air and prevents the air from migrating back into the chamber.